This Animal Model Core will be responsible for ordering mice, scheduling their use, performing the various manipulations required to induce experimental colitis, maintaining a barrier facility performing routine surveys to insure absence of any pathogens in the colony, and assist in the harvesting of tissues from such mice. Centralization of these functions in an Animal Model Core provides uniformity and quality control of mouse models being studied in the various projects, reduces cost because each project will not have to prepare and maintain their own animals, and conserve numbers of mice by ensuring maximal use of each one in the various projects. A centralized pathologic analysis, including scoring of colonic or intestinal inflammation, is performed for each project through this Core.